The one on my WSM 18 1/2 seems to be OK. Maybe you should remove it and check it in a pot of boiling water.
Lang 36 patio
18.5" Weber Smokey Mountain
22.5" Weber OTG with Cajun Bandit Conversion Kit
Char-Griller Akorn with side cart
1999 Weber Master-Touch - bent but not broken
14.5" Weber Smokey Joe Silver